diff --git a/tests/calc.at b/tests/calc.at
index 34cac69d..5fd441cf 100644
--- a/tests/calc.at
+++ b/tests/calc.at
@@ -40,8 +40,10 @@ AT_DATA([calc.y],
 
 %{
 #include <config.h>
-/* We don't need a perfect malloc for these tests. */
+/* We don't need perfect functions for these tests. */
 #undef malloc
+#undef memcmp
+#undef realloc
 #include <stdio.h>
 
 #if STDC_HEADERS